In four of our initial five cases of percutaneous cholecystostomy, performed under ultrasound guidance for septicemia due to suspected cystic duct obstruction and hydrops of the gallbladder, patients suffered profound vagal reactions with severe hypotension and bradycardia. One patient had cardiac arrest. The patients had experienced recent myocardial infarction, ventricular ectopy, or septicemia, and each had a greatly distended gallbladder. The reactions occurred immediately, though in the first patient recognition was delayed. One patient had infected bile, three had obstructing cystic duct stones with inflammatory response, and one had a sterile and nonobstructed gallbladder. All patients survived the acute insult. Treatment consisted of minimizing intravisceral manipulations, administration of intravenous atropine, fluids, antibiotics, and dopamine. Atropine administered prior to the procedure appeared to blunt the reaction in one patient. Two patients died within a week of other causes. At autopsy neither peritoneal cavity had bile staining. The other patients had follow-up ultrasound examinations; no intraperitoneal fluid collections were seen.